Dwell time as a %

[Frank Mallory]

Sean Connelly wrote:
> 
> Can someone help me... I am trying to work outthe ignition coil dwell time
> expressed as a % for various engine combinations but I am getting confused.
> 
> I know the time for one engine rev (in ms), coil dwell time (in ms) and
> number of cylinders (1, 2, 3 or 4) so how do I get dwell time ?
> 
> Is it
> 
>     Dwell(%) = (Dwell Time / (Time for 1 engine Rev / # Cylinders)) * 100
> 
> Sorry its such a trivial problem, but the easy ones are sometimes too
> easy and you miss them completely.
> 
> Cheers
> 
> Sean Connelly.

I think you have to divide by 2 (or use time for 2 engine revs) to
account for the fact that in the Otto-cycle gas engine, the engine
revolves twice for every revolution of the camshaft.

To convert from percent to degrees dwell, multiply by:
	90 for a 4-cyl. engine
	60  "  " 6-cyl.    "
	45  "  " 8-cyl.    ".